A REVIEW OF RECENT RESEARCH ON THE CATHAYSIA-FLORA IN ASIA

This paper attempts to give a brief review of research on the Cathaysia flora during the last 20 years in China and other countries. The paper also briefly discusses the origin, development, migration and extinction of this flora from the Late Carboniferous to the close of the Permian. THE CATHAYSIA FLORA has been known world-wide since early in the present century as the predominant Permo-Carboniferous flora of the Sino-Korean paraplatform of East Asia. Originally called the Gigantopteris flora, the name of this flora has been subsequently changed (Halle, 1937) because its most typical plants, the gigantopterids, which are nearly all found in the higher beds of this region, represent only the latest phase of the flora and not the characteristic elements of the whole Permo-Carboniferous in East Asia. The most important work dealing with the Cathaysia flora was contributed by the noted paleobotanist Prof. Halle (1927) under the title "Paleozoic Plants from Central Shansi." This monograph provides not only an excellent example of the study of a Permo-Carboniferous flora in East Asia, but has also proved to be an indispensable reference with which to begin the study of floras of the same ages, and their stratigraphy, in other countries. In many respects this work has had a tremendous influence on the fields of geology and paleontology. The fossil plants dealt with in this monograph come mainly from the Upper and Lower Shihhotse formations near Taiyuan, Shansi. It provides little information about older floras, such as those from the Taiyuan series and the Shansi formation (known formerly and collectively as 1 Received for publication 24 October 1980; revision accepted 8 January 1981. The authors are greatly indebted to Prof. Jane Gray, Department of Biology, University of Oregon, for giving us so much help in rewriting the English manuscript of this paper when she visited our Institute in the autumn of 1980. Dr. Li Xingxue was a delegate from The People's Republic of China to the United States in 1979 under the sponsorship of the Botanical Society of America and the National Science Foundation. the Yuehmenkou coal series), and it provides no definite boundary either to the upper or lower limits of the Shansi formation. As a result, many problems have remained unsettled for a long time, such as the geological and geographical distribution of some fossil plants and the ages and correlation of the strata concerned. In the last 40 years or so, greater importance has been attached to new finds of the Cathaysia flora in various regions, and as a result significant achievement has been made in understanding this flora. It is especially noteworthy that work on the type-section of the Taiyuan series and Shansi formation in North China and the Lungtan formation (or the Gigantopteris coal series) in South China and other important regions carried out in the past 30 years by the paleontologists of New China have enabled us to get a better understanding of the Cathaysia flora and to work out solutions for such problems. Following is a brief account of the accomplishments made by our geologists and paleontologists since the 1960's. By summing up important data both for China and abroad, we hope to encourage discussion about the composition, basic character, identification and classification of some typical genera and species, and the geological and geographical distribution of the Cathaysia flora as its phytogeography, origin, development, migration and extinction. STUDIES ON THE CATHAYSIA FLORA IN NORTH CHINA-Latest observations on the Permo-Carboniferous type-section of Taiyuan-The Permo-Carboniferous section near Taiyuan is well exposed and rich in both animal and plant fossils and many important works have been published both in China and abroad on this material. Consequently, this section has